2015-08-03  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66917
	* tree-vectorizer.h (struct dataref_aux): Add base_element_aligned
	field.
	(DR_VECT_AUX): New macro.
	(set_dr_misalignment): Adjust.
	(dr_misalignment): Likewise.
	* tree-vect-data-refs.c (vect_compute_data_ref_alignment):
	Compute whether the base is at least element aligned.
	* tree-vect-stmts.c (ensure_base_align): Adjust.
	(vectorizable_store): If the base is not element aligned
	preserve alignment of the original access if misalignment is unknown.
	(vectorizable_load): Likewise.

From-SVN: r226487